Drawing glass sheets



March Q 1 9926 15765 446 W. a... MQNRQ DRAWING GLASS SHEETS Filed April 25. 1920 Patented Mar 9, 1926.

PATENT OFFICE.

WILLIAM L. IONBO, OI PITTSBURGH, PENNSYLVANIA, ASSIGNOR 'IO GLASS MACHINE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPGRATION OF NEW JERSEY.

DRAWING GLASS SHEETS.

Application filed April as, 1920. Serial No. 375,972.

To all whom it may concern:

Be it known that I, .WILLIAM L. MONRO,

of Pittsburgh, Allegheny County, Pennsyl Vania, have invented a new and useful Improvement in Drawing Glass Sheets, of

which the following is a full, clear, andexact description, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is a diagrammatic longitudinal section showing a portion of the apparatus arranged for carrying out my invention;

Figure 2 is an elevation showing one form of the bending rolls and tension rolls;

Figure 3 is a view similar to Figure 2, showing another form of the bending rolls; and

Figure 4 is a diagrammatic view illustrating another modification.

My invention relates to the drawing of sheet glass and particularly to the continuous drawing of sheet glass over a bending roller by which it is bent from agenerally vertical direction to a generally horizontal direction. In such a drawing operation, it has been found that the bending roll makes defective glass, the roll surface impartingsurface defects, such as pimples, embedded foreign matter, etc., to that surface of the sheet which contacts therewith. M invention is designed to overcome this didiculty, and consists in providing a bending roll system which avoids contact of the wit system with the greater portionof the glass sheet, the thickened edge portions of the sheet being the only ones which contact with the bending roll system.

In the drawing, referring to the form of Figures 1 and 2, 2 represents the end portion of a tank furnace which extends to the right of the figure. 3, 3 are water coolers to cool and set the rising sheet. The sheet is prefen ably drawn with thickened edge portions which are preferably engaged just above the meniscus by friction brake devices, shown as pairs of rolls 4, 4, projectin inwardly from the sides and engaging t ese thickened edge portions. These stub rollers may be provided with any suitable amount of friction or drag by brake devices applied to their portions exterior to the drawing chamber. They thus impart any desired amount of drag or tension to the sheet as it rises. In this form, 5, 5 indicate two bending rolls forming a bending roller system which en ably through a flattening chamber, and then through an annealing chamber, by any desirable means.

In Figure 3, I show a form similar to Figure 2, except that the bending rollers 5 are secured to a sleeve 7 splined to a continuous shaft 8, extending through the drawing chamber. In this case, of course, ower may be applied to-one end only of the ending roll system if it is desired to drive the same.

Instead of drawing the sheet by grippers 0r-power applied after passing the bending roll, I may draw the sheet by gripping its edge portions between edge rolls 5 and driven rolls 9, as shown in Figure 4. In this case, the, rolls 9 will preferably be stub 'rolls or separated rolls, such as shown in wherever desired in the drawing chamber to assist in reheating the glass for bending or for any other purpose.

The advantages of my invention result from the use of a bending roll system which avoids contact of the bending roller with the A glass sheet proper, the bending being eifected by engaging the thickened edge portions which are removed after the glass has passed through the annealing leer and cut into sheets. I thus avoid the marring or defacing of the bending roll side of the continuous glass sheet by action of the bending roll surface thereon. If the sheet tends'to sag down between the bending rolls, this will be overcome in the succeeding flattening operation, which may be carried out by the fiattening devices indicated at. 10 and 11 in Figure 1. 1

The bending roll system may be drivenfor this purpose wherein contact is avoided between the bending roll and the under surface of the glass sheet.

I claim:

1. In apparatus for drawing sheet glass in a generally vertical direction and thence in a generally horizontal direction, means for imparting thickened edges to the sheets, and a bending roll system engaging said thickened edge portions and out of contact with the sheet proper, substantially as described.

2. In apparatus for drawing sheet glass in a generally vertical direction and thence in a generally horizontal direction, a drag roll system arranged to impart a tension to the glass sheet, and a bending roll system arranged to contact with the under surface of the edge portions only of the sheet, substantially as described.

3. Apparatus for drawing sheet glass, comprising a bath from which a sheet of glass is drawn, a pair of bcnding roll por tions engaging the edge portions only of a drawn sheet, the bendingroll portions being a substantial distance above the bath, and width maintaining means associated with each sheet edge adjacent the bath.

4-. Apparatus for making sheet glass, comprising a source of molten glass, a plurality of spaced apart bending roll portions adapted to change the direction oftravel of a sheet formed at such source, the portions of the sheet between such bending roll-portions being out of contact with the bending roll, and means associated with the sheet edges adjacent such source for maintaining the width of the sheet.

5. Apparatus for making sheet glass, comprising a source of molten glass, a plurality of spaced apart bending roll' portions adapted to change the direction of travel of a sheet formed at such source, the portions of the sheet between such bending roll porm'zaeee tions being out of contact with the bending roll, and means adjacent the source for i maintaining-the width of the sheet, said means engaging the same portions of the sheet as are afterwards engaged by the bend ing rollportions.

6. Apparatus for drawing sheet glass, comprising a bath of molten glass, means for reducing the temperature of a portion of such bath so as to define a region of lower temperature from which a sheet of glass may be drawn, a plurality of bending roll portions'spaced from said bath and so positioned as to draw a sheet from the region of lower temperature in the bath, the bending roll portions being spaced apart and adapted to change the direction of travel of the sheet, the portion of the sheet between such portions being out of contact with the bending roll, and means associated with the sheet edges adjacent the bath for maintaining the width of the sheet.

7. Apparatus for drawing sheet glass, comprising a bath of molten glass, means for reducing the temperature of a portion of such bath so as to define a region of lower temperature from which a sheet of glass may be drawn, a plurality of bending roll portions spaced from said bath and so positioned as to draw a sheet from the region of lower temperature in the bath, the bend- WILLIAM L. MON R0. 

